Key



G. A.. SYLVAIN.

KEY.

1,350,749, PatentedAug. 24,1920.

UNITED STATES PATENT OFFICE.

KEY.

Specification of Letters Patent.

Application filed November 18, 1919. Serial No. 338,838.

To all whom t may concern Be it known that I, GEORGE ALEXIS SYL- VAIN, a subject of the King of Great Britain, and resident of ttawa, in the Province of Ontario, Dominion of Canada, have invented certain new and useful Improvements in Keys, of which the following is a specification.

This invention relates to improvements 1n keys, and the objects of the invention are to prevent a door being opened by turning the key from the outside thereof, by means 1nserted through the keyhole to engage the end of the key.

Further objects are to generally improve and simplify the construction of keys of this type, and it consists essentially of the improved construction, hereinafter described in detail in the accompanying specification and drawings.

In the drawings:

Figure 1 is a plan view of the end of the key made according to the present invention, drawn to an enlarged scale to better show the construction.

Fig. Q is a sectional view through the end.

Fig. 3 is an end View with the rotatable plug in section.

Referring to the drawings, A represents the key, the shank 10 of which has a recess 11 bored in the end, the recess being formed with a projecting annular wall 12 divided into sections by a plurality of radial cuts 13, whereby the space between the cuts forms tongues 14 which may be bent inwardly.

15 represents a plug having a reduced inner portion 16 adapted to fit the recess 11 and terminating in a groove 17 having a beveled lower edge 18 against which the tongues 14 are adapted to bear.

In assembling the key the reduced portion 16 of the plug is inserted in the recess 11, the tongues lei are bent inwardly, thereby holding the plug 15 in position, permitting it to turn in the recess.

It will be seen that the key is of simple construction, but of suoli a nature that it may be easily manufactured in large quantities in automatic turret lathes and like machinery at low cost. The rotatable plug 15 will prevent the end of the key being engaged by pincers or other tools from the exterior of the lock.

' s many changes could be made in the above construction, and many apparently widely different embodiments of my invention, within the scope of the claims, Constructed without departing from the spirit or scope thereof, it is intended that all matter contained in the accompanying specification and drawings, shall be interpreted as illustrative and not in a limiting sense.

lVhat I claim as my invention is z 1. A key having a shank with a recess formed in the end of the same, and a pro` jecting flange formed with radial cuts dividing it into a plurality of tongues, 'adapted to be bent inwardly, a plug having a re` duced portion to it the recess, and formed with a groove adapted to be engaged by the tongue when bent inwardly.

he key according' to claim 1, in which one side of the groove is formed with a beveled surface 18, against which the tongues are adapted to bear.

In witness whereof I have hereunto set my hand.

Groen ALEXIS SYLVAIN.

Patented Aug. 24, 1920. 

